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排序方式: 共有389条查询结果,搜索用时 31 毫秒
1.
Effects of non-Gaussian concentration fluctuations in real time photon correlation spectroscopy were investigated with several sizes of mono-disperse polystyrene latex particles. The non-Gaussian correlation model for a full or a quasi-full (scaled) correlator showed good performance for particle sizing in the case of scaled correlation. The clipped correlation showed an equivalent performance with the scaled correlation except for the case of non-Gaussian fluctuation, where the measured diameter became inaccurate more rapidly with decreasing particle concentration in the scattering volume. The cause of such an instability of PCS in the clipped mode is attributed to baseline fluctuations of the correlogram induced by information loss of the clipped correlator. 相似文献
2.
Akira Ishizaki Kazuhiko Takasaki Shoji Shimomura Kouichi Masaki Kanji Kitazawa 《Electrical Engineering in Japan》1996,116(5):128-137
Although brushless resolvers have been used widely as angular position transducers, they are expensive due to their intricate construction, involving a rotary transformer to supply the exciting coils wound on the rotor poles with the current. It is shown theoretically in this paper that the resolver without rotary transformer or brushes can be realized by simple construction, which consists of the stator core with both 4-poles exciting windings and 2-poles output ones and the rotor core carrying no windings. In this resolver the rotor core has minimum gap at one side and a maximum gap at another side of the diameter. It is characterized by an outer surface form that makes the fluctuation part of gap permeance very in proportion to cos θ, where θ represents the angular position of a point in the air gap with respect to the origin on the rotor, the point of minimum air gap. The method determining the rotor form to embody the aforementioned gap permeance variation is also shown. It has been confirmed not only by simulation but also experiment that the 2-phase output voltages of a model designed based on the theory have sinusoidal waveforms with very small harmonic contents. Moreover, the rotor position detected by processing the output voltages through the conventional resolver/digital converter was within acceptable engineering accuracy. 相似文献
3.
4.
The Spiro compound N3P3(OCH2CF3)4(NH)2Si(CH3)2 formed by reaction of 1,1-diamino-3,3,5,5-tetrakis(2,2,2-trifluoroethoxy)cyclotriphosphazene N3P3(OCH2CF3)4(NH2)2 and dimethyldichlorosilane Cl2Si(CH3)2 is a yellow or orange coloured oil soluble in organic solvents, vapourized at 160°C without decomposition, and not hydrolysed appreciably in boiling water. Linear compounds are formed by reaction of N3P3(OCH2CF3)4(NH2)2 with diphenyldichlorosilane or phenyltrichlorosilane owing to hindrance of the phenyl radical. These compounds are amorphous or tacky solids, soluble in organic solvents and stable to water. 相似文献
5.
Takaho Kaneda Toshio Katsura Kanji Nakagawa Hiroshi Makino Masao Horio 《应用聚合物科学杂志》1986,32(1):3151-3176
The polyimides based on 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) described in Part I of this series were dissolved in p-chlorophenol and spun into fibers using a coagulating bath of ethanol. The fibers as spun had in general low tenacities and low moduli, but a heat treatment at 300–500°C under tension produced a remarkable increase in strength and modulus, and fibers with a tensile strength of 26 g/den (3.1 GPa) and an initial modulus higher than 1,000 g/den (120 GPa) could be obtained. Thus, the annealed fibers of polyimides are comparable to aramid fibers in mechanical properties. To heating in air and in the saturated steam, the polyimide fibers showed higher resistance than the aramid fibers. The polyimide fibers surpassed the aramid fibers in resistance to acid treatment and ultraviolet (UV) irradiation, but were inferior in resistance to alkali treatment. The annealed fibers of polyimides displayed distinct X-ray diffraction patterns. The chain repeat distance of 20.5 Å determined on the fibers of polyimide prepared from BPDA and o-tolidine, and 20.6 Å determined on the fibers of polyimide derived from BPDA and 3,4′-diaminodiphenyl ether are reasonable when the dimensions of monomeric units and the shapes of the molecular chains are considered. The X-ray reflections of both polyimide fibers were indexed satisfactorily on the basis of postulated unit cells. 相似文献
6.
Poly(anilino sulphamicphosphazenes) such as [NP(HNC6H5)2–x
(HNC6H4SO3H)
x
]
n
for polymer (I) x=0.3 and for polymer (II) x=0.8 were prepared by the reaction of poly(anilinophosphazene) [NP(HNC6H5)2]
n
and sulphonic chloride HSO3Cl in tetrachloroethane solvent several timeS. Also, H protons in the polymer (I) and (II) were prepared from lithum hydroxide in aqueous solution. It was found, by chemical analysis, that the product prepared with (I) and (II) had compositions such as [NP(HNC6H5)1.7 (HNC6H4SO3H)0.1(HNC6H4SO3Li)0.2]
n
(III) and [NP(HNC6H5)1.2(HN-C6H4SO3Li)0.8]
n
(IV). Also, the resistivity of products (III) and (IV) were determined and found to be 3.3×107 and 1.5×107 cm–1, respectively. 相似文献
7.
The crystallization process of Pd74Si18Au8 amorphous alloy has been investigated by transmission electron microscopy, small angle X-ray scattering and three-dimensional atom probe techniques. Although literature suggests that the alloy decomposes into two glassy phases prior to the crystallization, we found that the crystallization occurs directly from a single amorphous phase by the primary crystallization of fcc Pd–Au solid solution, followed by the polymorphous crystallization of the remaining amorphous phase to a Pd3Si phase. 相似文献
8.
Sunarso Riki?ToitaEmail authorView authors OrcID profile Kanji?Tsuru Kunio?Ishikawa 《Journal of materials science. Materials in medicine》2016,27(8):127
Bone-forming cells and M? play key roles in bone tissue repair. In this study, we prepared a superhydrophilic titanium implant functionalized by ozone gas to modulate osteoconductivity and inhibit inflammatory response towards titanium implants. After 24 h of ozone gas treatment, the water contact angle of the titanium surface became zero. XPS analysis revealed that hydroxyl groups were greatly increased, but carbon contaminants were largely decreased 24 h after ozone gas functionalization. Also, ozone gas functionalization did not alter titanium surface topography. Superhydrophilic titanium (O3–Ti) largely increased the aspect ratio, size and perimeter of cells when compared with untreated titanium (unTi). In addition, O3–Ti facilitated rat bone marrow derived MSCs differentiation and mineralization evidenced by greater ALP activity and bone-like nodule formation. Interestingly, O3–Ti did not affect RAW264.7 M? proliferation. However, naive RAW264.7 M? cultured on unTi produced a two-fold larger amount of TNFα than that on O3–Ti. Furthermore, O3–Ti greatly mitigated proinflammatory cytokine production, including TNFα and IL-6 from LSP-stimulated RAW264.7 M?. These results demonstrated that a superhydrophilic titanium prepared by simple ozone gas functionalization successfully increased MSCs proliferation and differentiation, and mitigated proinflammatory cytokine production from both naive and LPS-stimulated M?. This superhydrophilic surface would be useful as an endosseous implantable biomaterials and as a biomaterial for implantation into other tissues. 相似文献
9.
Masato Yamamura Toshihisa Kajiwara Hiroyuki Kage 《Chemical engineering science》2003,58(17):3891-3899
We present a compact formula for describing the mean frictional forces acting on a molecule in multicomponent systems. The friction-based diffusion theory of Zielinski and Hanley was extended to newly include the friction-average molar velocity as a reference frame. The results showed that the previous diffusion theories are unified by the friction-average concept by properly choosing the average velocity. The present model based on the diffusivity-related molar average velocity provides better predictions for the diffusive flux in a ternary miscible liquid compared to the other existing theories. The application of the model in phase-separating ternary systems revealed that the introduction of a highly diffusive third component into demixing polymer blends promotes a particular enhancement of the spinodal decomposition due to the difference in the frictional interactions between polymers. 相似文献
10.